Consider the following frequency distribution:
Class | 0 - 5 | 6 - 11 | 12 - 17 | 18 - 23 | 24 - 29 |
Frequency | 13 | 10 | 15 | 8 | 11 |
Find the upper limit of the median class.
To find median class,
Assume Σfi = N = Sum of frequencies,
fi = frequency of class intervals
and Cf = cumulative frequency
Lets convert this data into exclusive type of data.
CLASS INTERVAL | FREQUENCY(fi) | Cf |
- 0.5 - 5.5 | 13 | 13 |
5.5 - 11.5 | 10 | 13 + 10 = 23 |
11.5 - 17.5 | 15 | 23 + 15 = 38 |
17.5 - 23.5 | 8 | 38 + 8 = 46 |
23.5 - 29.5 | 11 | 46 + 11 = 57 |
TOTAL | 57 |
So, N = 57
⇒ N/2 = 57/2 = 28.5
The cumulative frequency just greater than (N/2 = ) 28.5 is 38, so the corresponding median class is 11.5 - 17.5.
∴ Upper limit of this median class = 17.5